Costs of electric vs gas water heaters
This may be old news to some, but surprised me. I needed to replace a small water heater and assumed usage costs of a gas unit would be much cheaper. (Cost to purchase the units is quite similar). Electricity around here is pretty cheap, but gas prices are way up. Even without adding in the “delivery and service charges” ($15) for NG I found that using a NG unit wouldn’t save much, if any, money. Electric units are reputed to have about the same life span, no venting issues, and are about 93% efficient. Plus, I could someday generate electricity with solar panels, but I haven’t found a way to generate ‘significant’ amounts on NG yet. <G>
Thon
Replies
>>"Plus, I could someday generate electricity with solar panels, but I haven't found a way to generate 'significant' amounts on NG yet. <G>
Guess it always pays to check up on longstanding "conventional wisdom." Every couple years I do the oil versus NG for heating and seems that even though oil lags NG some years, they basically catch up with each other over the long haul.
Also remember that solar can give you hot water directly. Don't need to convert to electric first and then reconvert to heat. ;-)
"Let's get crack-a-lackin" --- Adam Carolla
<Also remember that solar can give you hot water directly. Don't need to convert to electric first and then reconvert to heat. ;-)>Good point. And solar hot water is generally advised as the first solar upgrade to make.
Central Kansas?
Depending on your house, you might do very well with a heat pump water heater. We run ours seasonally, provides half of our substantial dehumidification needs while heating water at almost 3x the efficiencey of elec resistance. Beats even solar when the byproduct is cool dry air. Ours is tankless, used instead of resistance during the summer. Paid for itself in just over 1 season.
PAHS Designer/Builder- Bury it!
Tom:
Seems like you just about got it got it all in reducing the energy costs!! Just got to get an ethanol producer going for the vehicles and the hard liquor.....costs will really go down again.
For years, been trying to find an application for heat pump water heaters up in my climate (so I could be the first to sell them) but to no avail.
Part of my gov't job was to write and enforce the regs for the Energy Efficient Appliances Act.
The standard center flue natural draft chimney vented gas or oil water heater is only about 60% efficient overall. They may burn the fuel at 80%+ efficiency but lose a fair amount of heat in stand by.
Wrapping these with insulation only saves a few % since most of their standby losses are up the chimney, not through unit surfaces. After the firing cycle, heat from the hot water heats air in the center flue which then begins a convective air current up the chimney. This brings more cool air into the flue to be heated and continue the heat loss up the chimney.
A standard electric tank usually is 88-92% efficient as bought. A few tricks when buying and installing can bring that up to 97-98%.
(1) Choose a tank with a low side cold water inlet.
(2) Sit the tank on a piece of plywood over 1" of foam.
(3) Install a heat trap on the hot water outlet on the top.
(4) Install 5-6 feet of foam pipe insulation on both supply and outlet pipes.
(5) Install a 2" insulation wrap over all tank surfaces
Total cost of the extras is $30-40 and should pay for itself in about a year. Other benefits:
(1) Insulation and heat traps can be re-used in 10-12 years on a new tank
(2) Electric tank does not need burner servicing/tune up/safety checks each year. (these cost $$)
With apologies for a hijack...
Yup, I'm cheap. Doin' pretty well, always room for improvement. You know anything about earth tubes? Part of the PAHS program I bypassed. Fear of mold growth. Legionnaires' disease and all. Would decrease my annual temp swing by 50%! Not that it's uncomfortable now.
Have a conversation going on another list. I mentioned that the only surface I know that absolutely won't grow mold is boat hull paint. Nasty stuff to spray. Breathe it and die. Next best fungicide is my copper siding. So how about copper earth tubes? Might be a test in order. I can clean moldy incoming air with UV, but don't want another active system. That's the whole point here, passive. So I don't have to do, or pay for, much of anything. Lazy and cheap, that's me. And I'll work hard getting there. <G>
I looked at diesel alternatives, my main fuel, but no go so far. Hmmm... main, other than vino. And I'm not growing grapes, which is the easy part. Seems to me ethanol is over-hyped, not a panacea. I won't go into details, but if you're interested I can point you to a list originally concerned with soil quality. Something I'm interested in. We grow groceries on the roof. No-till of course. Getting close to permaculture. Did I mention I was lazy? Woodgas is kinda interesting.
Idly looked at alternative generators today, generally heat run. I have large enough machinery that off-grid doesn't make a lot of sense. But I keep looking. Hooking a Caterpillar up to my PTO generator via hydraulics works, but isn't inexpensive or remotely green. Now, if I had a couple other families nearby...
Heat pump water heaters... Mine works great when the house's coasting 70º or better. Not yet turned on. Saves us 2º max summer temp plus 1/2 our dehumidification. It was a no-brainer. Ebay helped with the payback, new-old stock. Seems somebody in Florida had a stash. Guy I built a similar house for jumped on one too. Helps if the house is configured correctly. Ours are. Beware hooking one up with an electronically controlled water heater. Mismatch.
Application is easy if summers are hot, especially if they're humid too. Kansas sounds ripe. Nova Scotia? PAHS Designer/Builder- Bury it!
Humidity? We ain't got no stinkin' humidity here in central KS. <G> In Kansas City however, it was brutal.You say 'depending on your house' regarding a heat pump. Brief explanation?Thanks.Thon
You have to get air into and out of the heatpump. The cool dry air coming out wants to be distributed in your house. We use house air for the makeup to maximize return. The heatpump would prefer outside air for makeup, if it was hotter.
PAHS Designer/Builder- Bury it!
Edited 5/8/2006 9:44 pm ET by VaTom
I have been consicering the same question. Even though a tankless gas hot water heater is three times the price of an electric tank, it is only heating water on demand so that you aren't maintaining 40 to 80 gallons even when you are not there.
Another solution would be to do the same thing with electric heaters at the source of need, (bathrooms, kitchen, etc.) which heat water when it senses the a pressure drop at the tap. These have been used abroad for years and still are slow in catching on here.
Bobalu in NJ